IgA anti-actin antibodies in celiac disease

The purpose of this study was to determine the sensitivity and specificity of IgA anti-actin antibodies (IgA-AAA) for celiac disease (CD), to investigate their usefulness as a marker of compliance in CD patients to the gluten-free diet (GFD), and to assess the relationship between their presence in the sera of CD patients and severity of intestinal mucosal damage.

A total of 182 patients with CD were studied: 63 patients were untreated; 50 patients were following a strict GFD; and 69 patients were non-compliant with a GFD. IgA-AAA was detected using a homemade enzyme-linked immunosorbent assay (ELISA).

IgA-AAA showed a sensitivity of 41.3% and a specificity of 71.4% for a diagnosis of CD. In children, the frequency of IgA-AAA detection was lower in those following a strict GFD (23.1%) compared with untreated patients (39.4%) and those not complying with a GFD (32.5%). In patients following a strict GFD, IgA-AAA detection was significantly less frequent in children than in adults (23.1% vs. 58.3%, respectively; P<0.001). IgA-AAA was found in 17 out of 52 CD patients with total villous atrophy (32.7%), and in one out of 11 patients with subtotal villous atrophy (9%).

IgA-AAA cannot replace anti-endomysium and anti-tissue transglutaminase antibodies in the diagnosis algorithm of CD, but it can serve as a reliable marker of severe intestinal mucosal damage in CD patients.